Forces & Fields

Question 1

What is the SI unit of charge?

Answer 1

The Coulomb (C)

Question 2

Describe the motion of a positive charge in a conductor.

Answer 2

A positive charge cannot move in a conductor.

Question 3

How is a charge distributed in a conductor?

Answer 3

Evenly along the surface.

Question 4

How is a charge distributed in an insulator?

Answer 4

The charges remain fixed in place.

Question 5

What is the smallest unit of charge found in ordinary matter?

Answer 5

The elementary charge (e) = 1.60 x 10^-19 C

Question 6

What is the Law of Conservation of Charge?

Answer 6

The net amount of charge in any process is conserved.

Question 7

What will occur if a charged object touches a neutral conductor?

Answer 7

Electrons will move from the object to the sphere.

Question 8

What are point charges?

Answer 8

Charged objects that a very small relative to their distance apart.

Question 9

What is the process of determining the direction of an electric field?

Answer 9

Determining which direction a positively charged particle would travel.

Question 10

What equation is derived from Coulomb’s law?

Answer 10

Fe = (k x q1 x q2)/r^2

Question 11

Where is a charge located on a hollow conductor?

Answer 11

The outside. The inside will remain neutral.

Question 12

What the units that measure field strength?

Answer 12

N/C

Question 13

What is electric flux?

Answer 13

The measure of the electric field lines passing through a surface perpendicular to the field.

Question 14

What is “q” in E = Fe/q?

Answer 14

q = to a test charge in an electric field

Question 15

What is Q in E = (k x Q)/r^2?

Answer 15

Q = to a source charge

Question 16

At what distance between to charges is the electrical potential energy zero?

Answer 16

Infinite!!! (doesn’t happen in nature)

Question 17

What is the electrical potential energy between two charges dependant on?

Answer 17

The distance between the two charges.

Question 18

What is meant when the electrical potential energy is negative?

Answer 18

The electrons are in a bound state.

Question 19

What is the electric potential?

Answer 19

The electric potential energy per unit of charge. J/C or V

Question 20

What is electric potential completely dependant on?

Answer 20

Location

Question 21

What are equipotential lines?

Answer 21

Areas in which the force exerted in a field are equal. It takes no work to move in an equipotential line.

Question 22

What are the units of Newtons?

Answer 22

Kg(m/S^2)

Question 23

What are the units of Joules?

Answer 23

N m or Kg(m^2/s^2)

Question 24

What kind of current flows negative to positive?

Answer 24

Electron

Question 25

What kind of current flows positive to negative?

Answer 25

Conventional.

Question 26

Describe the first hand rule.

Answer 26

Thumb points in the direction of the current. Fingers then curl in the direction of the magnetic field. Use your right hand for conventional current and your left hand for electron flow.

Question 27

Describe the second hand rule.

Answer 27

Grasp the solenoid with fingers following the current flow. The thumb then points to the north pole of the electromagnet. Use your right hand for conventional current and your left hand for electron flow.

Question 28

Describe the third hand rule

Answer 28

Lay your hand flat, with your thumb perpendicular to your fingers. Point your thumb in the direction of the current. Then point your fingers in the direction of the magnetic field. Your palm now points in the direction of the magnetic force. Use your right hand for conventional current and your left hand for electron flow.

Question 29

Describe the process of charging by friction.

Answer 29

When one material is rubbed against another material and an exchange of electrons occurs. This results in one material becoming positively charged and one becoming negatively charged.

Question 30

Describe the process of charging by conduction.

Answer 30

When a piece of charged metal touches a neutral one, charge transfers to the neutral one until both objects have the same charge.

Question 31

Describe the process of charging by induction.

Answer 31

Occurs when a piece of neutral metal is grounded, a charged object is placed near it, and the ground is removed while the charge is near. The neutral object becomes charged opposite to the charged object.